Light-Shrinking Material Lets Ordinary Microscope See In Super Resolution (phys.org) 19
Electrical engineers at the University of California San Diego developed a technology that improves the resolution of an ordinary light microscope so that it can be used to directly observe finer structures and details in living cells. Phys.Org reports: "This material converts low resolution light to high resolution light," said Zhaowei Liu, a professor of electrical and computer engineering at UC San Diego. "It's very simple and easy to use. Just place a sample on the material, then put the whole thing under a normal microscope -- no fancy modification needed." The work, which was published in Nature Communications, overcomes a big limitation of conventional light microscopes: low resolution. Light microscopes are useful for imaging live cells, but they cannot be used to see anything smaller. Conventional light microscopes have a resolution limit of 200 nanometers, meaning that any objects closer than this distance will not be observed as separate objects. And while there are more powerful tools out there such as electron microscopes, which have the resolution to see subcellular structures, they cannot be used to image living cells because the samples need to be placed inside a vacuum chamber.
The technology consists of a microscope slide that's coated with a type of light-shrinking material called a hyperbolic metamaterial. It is made up of nanometers-thin alternating layers of silver and silica glass. As light passes through, its wavelengths shorten and scatter to generate a series of random high-resolution speckled patterns. When a sample is mounted on the slide, it gets illuminated in different ways by this series of speckled light patterns. This creates a series of low resolution images, which are all captured and then pieced together by a reconstruction algorithm to produce a high resolution image. The researchers tested their technology with a commercial inverted microscope. They were able to image fine features, such as actin filaments, in fluorescently labeled Cos-7 cells -- features that are not clearly discernible using just the microscope itself. The technology also enabled the researchers to clearly distinguish tiny fluorescent beads and quantum dots that were spaced 40 to 80 nanometers apart. The findings appear in the journal Nature Communications.
Liu's team previously published a paper showing that his technology is also capable of imaging with ultra-high axial resolution (about 2 nanometers). They are now working on combining the two together.
The technology consists of a microscope slide that's coated with a type of light-shrinking material called a hyperbolic metamaterial. It is made up of nanometers-thin alternating layers of silver and silica glass. As light passes through, its wavelengths shorten and scatter to generate a series of random high-resolution speckled patterns. When a sample is mounted on the slide, it gets illuminated in different ways by this series of speckled light patterns. This creates a series of low resolution images, which are all captured and then pieced together by a reconstruction algorithm to produce a high resolution image. The researchers tested their technology with a commercial inverted microscope. They were able to image fine features, such as actin filaments, in fluorescently labeled Cos-7 cells -- features that are not clearly discernible using just the microscope itself. The technology also enabled the researchers to clearly distinguish tiny fluorescent beads and quantum dots that were spaced 40 to 80 nanometers apart. The findings appear in the journal Nature Communications.
Liu's team previously published a paper showing that his technology is also capable of imaging with ultra-high axial resolution (about 2 nanometers). They are now working on combining the two together.
"showing that his technology" (Score:2)
Re: "showing that his technology" (Score:2)
Re:"showing that his technology" (Score:4, Interesting)
Re: "showing that his technology" (Score:5, Informative)
The paper says which authors did what (by their initials): Y.U.L., J.Z., and Q.M. contributed equally to this work under the supervision of Z.L. Y.U.L., J.Z., Q.M., and Z.L. conceived and designed the experiment. Y.U.L., J.Z., Q.M., and Z.B. performed the experiments. L.K.K., Y.U.L., and Q.M. performed the simulations. C.P. prepared biological samples under the supervision of J.Zhang. Q.M. and G.L. fabricated HMM samples. G.B.M.W. performed SEM. Y.U.L., J.Z., and Q.M. reconstructed the images, analyzed the data, and created the figures. Y.U.L., J.Z., and Q.M. wrote the paper which was revised by all authors.
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Ordinary microscope? (Score:5, Informative)
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Re: Ordinary microscope? (Score:2)
Interesting perspective on the high radiation problem. Do you have references that show examples where research conclusions were wrong because the microscope radiation induced an unnatural cellular response, or that this is a widespread problem?
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This is similar to what amateur astronomers do when they take pictures of a bright object (like Mars or Jupiter) and stack them, right? Which results in photos taken with a ten or twelve inch telescope that look better than pictures taken 50 or more years ago with telescopes like the Yerkes 40 inch refractor.
the summary is wrong. (Score:5, Informative)
It turns out at the paper being cited doesn't shrink anything.
This sort of microscope falls under the general class of microscopes known as structured illumination microscopes (SIM).
There are three principles at work in a structured illumination microscope:
1. Instead of the image being taken in the near field, it is taken in the far field of the focal plane, which is the so-called fourier plane.
2. instead of typical kohler illumination (google it) the microscope uses a specially engineered phased-controlled light pattern.
3. multiple images are taken of a single object, each image taken with a unique light pattern (typically with phase control), then reconstructed with a deconvolution algorithm which follows the approximate rule: N-fold resolution improvement by taking N^2 images. The traditional SIM deconvolution algorithms assume knowledge of the PSF (which SIM seeks to decrease.)
The paper talks about a specially designed HMM used in conjuction with a rotating multimode fiber and a standard diffraction limited structured light device to generate structured light beyond the diffraction limit with enough randomness to provide taking hundreds of unique images. They take these images and then pass it through a blind deconvolution algorithm (presumably because of the random illumination pattern generated by the HMM). Obviously due to limitations in their approach, they report a resolution limit.
So there are a few differences between this and a standard structured illumination approach, but it is similar enough to understand.